Bevel edge grinder



Feb. 25, 1964 D. GRAY ETAL 3,121,979

BEVEL EDGE GRINDER Filed May 24, 1961 4 Sheets-Sheet 1 INVENTORS DOLPHGRAY 2 JACK S UDDARTH ATTORNEY Feb. 25, 1964 D. GRAY ETAL 3,121,979

BEVEL EDGE GR-INDER Filed May 24, 1961 4 Sheets-Sheet 2 INVENTORS DOLPHGRAY JACK SUDDARTH ATTORNEYS Feb. 25, 1964 D. GRAY ETAL 3,

BEVEL EDGE GRINDER Filed May 24, 1961 4 Sheets-Sheet s INVENTORS DOLPHGRAY ATTORNEY JACK SUDDARTH .mwd

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Feb. 25, 1964 -D. GRAY ETAL 3,121,979

BEVEL EDGE GRINDER Filed May 24, 1961 4 Sheets-Sheet 4 IIV/ INVENTORS IDOLPH GRAY JACK SUDDARTH ATTORNE 5 United States Patent 3,121,979 BEVELEDGE GRINDER Dolph Gray and Jack Suddarth, Muskogee, Okla, assignors toCoburn Manufacturing Company, Inc, Musicogee, Okla, a corporation of()lrlahoma Filed May 24, 1961, Ser. No. 112,378 17 Claims. (Cl. 51-101)This invention relates to an improvement in bevel edge grinding machinesand specifically relates to an edge grinding machine for forminggeometrical regular or irregular peripheral beveled edges on meniscusand toroidal shaped articles such as ophthalm c lens. I

An instrument according to this invention comprises in combination arotating gr-inding wheel having a V- groove abrading edge for formingthe bevel on the peripheral edge of the lens, a lens supporting meansfor placing the peripheral edge of the lens in contact with the grindingsurface of the grinding means, said supporting means imparting rotarymovement to the lens, means for imparting a desired movement in the lenssupporting means for maintaining the peripheral edge of the lens incorrect alignment with the bevel grinding surface, and means displacingthe lens supporting means causing the lens to advance towards, andrecede from, the V-groove in accordance with the peripheral contour ofthe lens, whereby said grinding wheel forms the desired bevel on theedge of said lens.

The movement of the lens supporting means and its displacement towardsand away from the grinding means is effected by a cam, the profile ofwhich corresponds to the finished peripheral shape of the lens. This camis mounted on a rotating chuck and, during the chuck rotation, effectsthe desired displacement of the lens supporting means.

One of the major objectives of this invention is to provide improvedstructure for guiding the peripheral edge of an ophthalmic lens into therotatable abrading element. This objective is accomplished throughstructure which positively controls the movement of the edge portion ofthe lens into engagement with the abrading element on a line constantlytangential to the radius of a selected curve for the particular lensbeing ground.

Another objective of this invention is to provide an ophthalmic lensedge-grinding instrument of rigid construction comprised of a series ofsub-carriages respectively limited to rectilinear movement but whosecombined movements causes the lens to follow a predetermined curvilinearpath into the abrading tool.

A still further objective of this invention is to provide a bevel edgegrinding machine which eliminates the need for floating head typeequipment now prevalent in the art. Such prior art equipment produces acurved beveled edge because of its sole dependence on the peripheralcontour of the pattern cam for its engagement with the grinding wheel.This causes S-curves in the beveled edge of the lens when the abradingwheel is confronted with a lens having varying thicknesses or contours.In contrast, this invention provides a tangential bevel edge which ismuch more desirable from a cosmetic point of view in glasses. Thetangential bevel is also much more desirable for mounting the lens in aframe.

A further objective of the invention is to provide a bevel edge-grinderwhich is adjustable to a selected curve of the lens, so that the lens asit rotatably engages the apex of the V-groove of the abrading apparatusWill be constantly aligned with respect thereto regardless of acondition change during grinding.

Another objective of the invention is to provide a machine of the typedescribed for moving an article toward and away from a grindinginstrument along a 3,121,979 Patented Feb. 25, 1964 tangent to theselected curve as determined from the prescriptive data known to anoperator.

A further objective of the invention is to provide a bevel edge-grindingmachine which is automatic in operation, rigid in construction,relatively inexpensive and simple in its manufacture, and operable in amanner completely divorced from the weight of the chucking mechanism.

A still further objective of the invention is to provide a novel meansby which the center of the convex surface of the lens (apogee) isrelated to the deepest portion of the V-shaped groove in the abradin-gwheel. In most existing apparatus, the lens is supported in such amanner that it travels in an arcuate path toward and away from thegrinding tool determined solely by the peripheral configuration and theselected radius. According to the present invention, the lens is fed tothe grinding tool along a continually changing tangential line which isperpedicular to the radius determined by the base curve of the lens. Inthis manner the apex of the bevel is consistently, within very closetolerances, an even distance from the convex side throughout the entireperiphery of the lens.

Another objective of this invention is to provide means by which theapex can be accurately positioned between the peripheral edges of theconcave and convex surface.

With the construction according to the present invention, the arcuatepath defined by a radius of the base curve is continually divided intoan abscissa and ordinant type components having corresponding movementsin supporting rectilinear moving carriages which combine to develop thedesired arcuate movement.

This rectilinear feed-in gives positive center line control of lens tothe diamond grinding wheel at all points along the perimeter of thelens. As a concurrent objective, this gives the operator full choice inselecting the bevel edge location.

A further objective of this invention is to feed the lens to be groundinto the groove of the grinding wheel so that the center line of thelens always remains perpendicular to the center line of the groove, andthe selected base curve tangent at the edge of the lens intercepts saidcenter line of said groove.

In order that the invention may be clearly understood and carried intoeffect, an embodiment of the same will now be described with referenceto the accompanying drawings, in which:

FIG. 1 is a front elevation of the apparatus according to the invention;

FIG. 2 is a plan view thereof;

FIGS. 3 and 3a are elevational views of a lens beveled with prior artdevices;

FIGS. 4 and 4a are elevational views of a lens beveled by the structureof this invention;

FIG. 5 is a plan view of a lens blank;

'FIG. 6 is a partial plan view of the carriage assembly with portionsbroken away; I

FIG. 7 is a sectional view along the line 77 of FIG. 6;

FIG. 8 is a partial sectional view along the line 88 of FIG. 2;

FIG. 9 is a diagrammatic plan view of the chuck assembly showing theinterior thereof;

FIG. 9a is an elevational view of an eccentric cam;

FIG. 9b is a partial end view of FIG. 9a;

FIG. 10 is a diagrammatic sketch showing the geometric movement of thelens supporting structure during different phases of the grindingoperation;

FIG. 11 is an enlarged schematic showing of the movements depicted inFIGS. 9 and 10;

FIG. 12. is a diagrammatic view of the bevel placement mechanism; and

FIG. 13 is a diagrammatic cross-section of the lenssize adjustmentassembly.

Referring now more particularly to the drawings and to the side views ofa group of lenses, it is apparent that the lenses shown in FIGS. 4 and4a are mounted in a frame much more readily than the ones shown in FIGS.3 and 3a. This is so because frames are normally constructed with aninterior peripheral groove to receive the exterior bevel of the lens.For reasons of economy, the frame manufacturer, although producingframes of many different peripheral configurations, cannot feasiblyproduce frames suitable for all prescriptive curves for each peripheralshape. Therefore, lens frames are provided with a straight fit. Thestraight bevels of FIGS. 4 and 4a, however, will always mate perfectlywith a straight groove in the framing members.

In providing beveled edges by prior art methods, the bevels throughoutthe peripheries of the lenses are not shaped to properly fit the framegrooves; that is, such lenses normally have the apex of their bevelsspaced at identical distances from the concave and convex surfaces ofthe lens at various points along the periphery. In such events the apexof the bevel will be irregular and crooked throughout the periphery ofthe lens as the major and minor curves change values. This necessitatesthe frame rim encircling the lens to be bent, twisted, reshaped orotherwise distorted to properly receive the lens. This is accompaniedwith the constant danger of imparting a strain on the lens and possiblebreakage thereof.

The above disadvantages are practically non-existent in the presentlydescribed device wherein the irregularly shaped lens or other article ismoved arcuately into and out of abrading position along a path relatedto the radius of a selected curve of the lens. The position of saidpath, with respect to the abrading wheel, being adjustable in accordancewith the characteristics of the lens being ground.

Referring now more particularly to the machinery of the invention and tothe drawings, where like characters of reference designate like partsthroughout the several views, the present invention is embodied in amachine having a cabinet "14 upon which a grinding apparatus 16 issupported. The cabinet 14 houses a power plant, an air compressor, theoil supply, drainage structure, and so forth, which are necessary to anygrinding Operation. The grinding apparatus is aflixed to the cabinet bya stationary base 18 upon which a grinding wheel assembly 20 and a lenspositioning chuck assembly 22 are mounted.

The lens grinding assembly 20 is supported for limiting pivotingmovement about a vertical shaft 21 in any convenient fashion. Theassembly further includes a grinding chamber 26 having a pivoted door 28closing the front access opening thereof. A circular V-grooved diamondabrading wheel 30 (FIG. 9) extends to within chamber 26 and is adaptedto be rotated by shaft 24. In the embodiment being described, theabrading wheel is vertically disposed in a plane defined by the apex 27of the groove and said plane is vertically normal to the hori zontalbase supporting member 13. To the rear of assembly 20 is a diamond wheelangle scale by which the angular attitude of the grinding wheel planemay be read as it is adjusted about shaft 21. The extension of the axisof shaft 21 intersects the apex of the 27 of the abrading wheel. Themost often used abrading wheel has a 115 (degree) groove. As can bereadily seen, the front slope (toward the convex surface) or the rearslope can be proportionately varied by moving housing 20 (andconsequently wheel about shaft 21.

The wheel 30 is driven about the shaft 24 by a belt 23 or anyconventionual connecting means to a motor within cabinet 14. Duringoperation, the assembly 28 is locked insofar as movement about shaft 21is involved and remains stationary except for the rotation of the wheel39.

The desired lens movement toward the abrading wheel is accomplished bymoving the assembly 22 with respect to the wheel along a controlledselected path. For these purposes, a lower L-shaped carriage 32 (FIGS. 6and 7) is mounted on base 18 for a straight line reciprocating motion inball bearing tracls 34. The tracks are comprised of a stationary plate36 having ball grooves 36' and 36" along its edges. The plate is securedin to base 18 by bolts 39. The carriage has a generally invertedU-shaped cross-section having a pair of inner rails 38 and 38 attachedto the legs of 32 and are formed with mating grooves opposing thegrooves of plate 36. Ball bearings as are disposed between the groovesfor substantially friction-free movement between the base and thecarriage.

A set screw 42 is threadedly received by the carriage and abuts theplate 36 and limits the movement of carriage 32 in the direction denotedby arrow 44.

A perpendicular extension 48 of carriage 32 supports a second uppercarriage 50 for longitudinal reciprocating movement normal to themovement of carriage 32. The ball-bearing support for carriage 50 iscomprised of a plate 52 affixed to extension 48 by screws 51, and asimilar ball-bearing arrangement. An adjustable set screw 54 is providedfor abutting the plate 52 to limit the upper carriages movement indirection 56. Along the edge of the upper carriage is an apertured lug58 receiving the piston rod of an air cylinder 60.

The piston rod 61 is pivotally connected to lug 58 by pin 62. Thecylinder end thereof is pivotally connected to base 13 via pin 64. Aircylinder 6% is the power means for moving carriages 32 and 50, andduring adjustment is powered to urge the carriages against set screws 42and 54; that is, away from the abrading wheel. Flexible air hoses 53 and53 supply air to the cylinder. The set screws are used to accuratelyposition the carriages and thereby provide a fixed point from which toposition the lens chuck with respect to the abrading wheel so thatfurther adjustments can be made for the particular lens to be beveled.

During operation, the chuck assembly 22 is secured to upper carriage 50and moves therewith. The assembly has a generally U-shaped configurationconsisting of a pair of upwardly extending sections 66 and 68 defining asaddle 27 therebetween, in which the grinding chamber 26 is received.Rotatably secured within section 66, is a chuck shaft 76 which supportsa pattern cam 72 at one end, and is faced with a resilient lens-engagingmaterial 74- surrounded by bushing 75 at the other end thereof. Shaft 70is supported by roller bearings 76 and 76 and thrust bearings 7 8.

A second chuck shaft 80, coaxial with shaft 70, is rotatably supportedin extension 68 by roller bearings 32 and 32' and thrust bearings 84.Shaft 80 is also faced at its inner end with a resilient lens-engagingmaterial 36. As stated, the shafts 7t) and 89 share a common axis 83 andare adapted to secure a lens blank therebetween. The outer end of shaft80 is equipped with a doubleacting air cylinder 90 for causingreciprocating motion in shaft 80 along axis 88. Shaft 70 issubstantially longitudinally stationary along axis 88 except for slightchucking variations which are accounted for. Air is supplied to eitherside of a piston head 93 via conduits 92 and 94. As seen in FIG. 9,pressure in conduit 94 has urged facing 86 to a lens-gripping positionwith facing 74. Air

pressure chucking and air pressure biasing is uniquely adapted for thesepurposes because of its uniformity and its infinite adjustability.

When the chuck shafts '79 and 80 securely grip a lens therebetween theyare caused to rotate as a unit through a power train comprising gears96, 96', 98, and 93'. The power train may be of any conventional designand is operated from the power source 97.

The carriages 32 and 50 are, through adjustment of screws 42 and 54, setto position the center of chuck face '74 a precise distance F from theapex of groove 27.

Since the lense blank must be positioned precisely with respect to thegroove, and since the precise position of the apogee 100 of a blank willvary depending on the curve of the convex surface, means are provided todetect this position. This means is comprised of a sensing rod 102slidably journaled within the extension 66, along the axis 88. The rodis biased by spring 104, through a dowel pin 106, to engagement with theapogee 161) of a blank centered between the chuck shafts. The apogeelocation sensing rod 102 is a constant length, and as the convex curveof the lens varies, the pin 106 will move accordingly in turn moving anattached slide collar 168 toward and away from the lens blank. About theexterior of the collar is a circumferential groove 110. A cam 112 ridesin the cam groove 111), and is connected to a shaft 114 by way of aneccentric 116. Shaft 114 is rotatably journaled in housing 22 by way ofbearing 118 and at its outer end is terminated by a position indicatingarm 120. FIG. 9a shows the member 121, which is comprised of cam 112,shaft 114, eccentric 116, and arm 12%. Therefore, a movement of rod 162produces a proportionate movement in arm 121 When the indicia marks 122and 124 are matched there is no curve on what would be the convex sideof the lens. When, through a movement of rod 1112, caused by the apogeedisplacement the indicia become mismatched, the handle 126 is rotateduntil they are rematched. The handle 126 is fixedly secured to athreaded sleeve 127 and a threaded bushing thereof 129 receives athreaded end 131 of the sleeve 127. The thrust bearing 78 absorbs thechucking pressure as chucking takes place when and if any movementoccurs in shaft 7 t) with sensing rod 162. This causes a movement ofindicator 126. Therefore, as handle 126 is moved in opposition to theprevious movements, shaft 7 it is moved back accordingly until indicator1219 is aligned with the hash mark 124. When this is accomplished, theapogee 109 is the distance F from the apex 27. The displacement distanceof the apogee 99 (the sagitta) for all lens, is determined by thedistance L between the plane defined by the diametric opposing points ofcontact on the convex surface of the annular bushing 75, and theparticular curve of the lens being chucked.

After carriages Z4 and 56 are adjusted to position the center of thechuck face 101 a distance F from the apex 27, and after accounting forthe displacement caused by the convex curve, it is necessary to positionthe housing 22 relative to the upper carriage 56 so that the crest ofthe bevel will be at a selected distance from the convex surface. Thehousing 22 is mounted to carriage 50 via dovetail slides 126. A shaft128 with a knob 130 at its outer end is threaded through assembly 22 andis threadedly received in a block 132 of carriage 50. A rotation ofshaft 128 will therefore move 22 with respect to 50. A rack 135 oncarriage 59 receives a pinion gear 137 which has a shaft 139 journaledthrough the side of housing 22. A rotation of shaft 128 causes amovement in carrier 22 which is reflected on a diopter scale dial 141.The dial is disposed opposite a bevel location scale 143 which isdivided in lens thickness increments in millimeters. If the lens has abase curve of 5 diopters, the lens to be ground is 2 mm. thick, and itis desired to locate the bevel crest 1 mm. from the periphery of theconvex surface at the base curve, the 1 mm. hash mark is disposedopposite the 5 diopter (see FIG. 12) setting by shaft 128. It can beseen that the bevel location can therefore be infinitely selected forany given base curve.

All pattern cams, such as 72, have a lens size diameter S (FIG. 13). Sis the horizontal diameter of the pattern when it is mounted onpositioning lugs 71 and 73 at the end of shaft 70. In order to insurethe proper size of the finished lens as well as the proper peripheralconfiguration, further adjustment mechanism is provided to adjust forvarying lens sizes. This structure is best seen in FIGS. 1 and 13.

The cam surface 73 is movable with respect to base 18 on dovetail slides180. Extending upwardly from base 18 is a journal 182 which receives athreaded shaft 184. Shaft 184 is connected to and rotatable with amicrometer knob 186. The varying diameters of patterns can thus be madeto contact with the surface 73 at the cor rect point for a particularsize. For instance, the solid line position of FIG. 13 could be for a 35mm. lens and the dotted lines for a 56 mm. position. The scale on theknob and its relation to the rest of the apparatus are preset so thatthe movement of the lens blank will closely follow the contour of thepattern.

Therefore, the mechanism is provided with means to accurately positionthe apogee of the lens at an initial point. Carriages 32 and 50 areaccurately related to base 18 by set screws 42 and 54. The housing 22 ispositioned with respect to carriages 32 and 56 via shaft 128 for bevellocation, and the curvature of the lens on its convex support isaccounted for via the sensing rod 102 and its associated structure. Nowthe structure for moving the lens into the tool along a desired pathfrom this accurately pre-determined point will be described.

The machine is set so that there is a fixed distance F between the apexof groove 27 and the point 101 when the chuck is supporting a lenshaving a fiat surface. Un- (ier present conditions, a distance of 1%inch has been found desirable for this distance.

A slide block 144 is received by tracks 146 along one side of base 18. Adepending journal 148 is slidably received by a groove 150 in the base.The journal threadedly receives a shaft 152 which has its outer endtenninated by hand-wheel 154. The block is provided with an indicia mark156 which is adjacent a diopter scale 158 on the base. Therefore, block144 is movable with respect to scale 158 by a rotation of shaft 152.

A radius arm 160 is pivotally mounted in block 144 via pin 162. The armis grooved at 164 throughout the major portion of its length. A pin 166riding in the groove 164 is pivotally received by a journal extension168 of upper carriage 56. A lock handle 176) is provided at the upperend of pin 166 and is equipped With a conventional lock mechanism tosecure the pin 166 at any selected point along arm 166. At the initialposition, the distance F is selected between pivot pins 162 and 166.Since carriages 22 and 50 are fixed with respect to a point on arm 166,once the handle is locked, the carriage 22 will move laterally only thatamount permitted by an arcuate movement of arm 161 The amount of lateralmovement permitted in carriage 56, for a given movement in carriage 32,is, of course, dependent on the distance between pins 162 and 166 andthe angle the radius arm makes with the direction of movement of theupper carriage 50. Therefore, the scale 158 is measured in diopters andthe position of mark 156 with respect thereto will determine the lateralmovement of carriage 34 with each concurrent movement in carriage 32.

In operation, air pressure is imparted to cylinder 60 in an operativedirection to pull the pattern cam 72 in engagement with the bearingsurface 73. The pattern cam is selected for the particular peripheralconfiguration desired in the lens. The chuck shafts are then rotated andthe lower carriage 32 will move longitudinally an amount permitted bythe varying diameters defined by the peripheral contour of the cam. Witheach longitudinal movement, a lateral movement occurs in upper carriage50 an amount permitted by the radius arm 160. For example, if a lens wasground according to the peripheral shape of that shown by the dottedline in FIG. 5, there would be a plurality of diameters from the centerC to each point on the periphery. Assuming that D is the least diameterand D is the greatest diameter, for the movement between D minus D, aconcurrent movement would be imparted as a result of the arcuatemovement of the radius arm. This can best be seen by referring to FIG.11 which is an enlarged view of this rectilinear progression.

It can be seen that by sliding block 156 along the diopter scale 158,the distance between pivot points 162 2 and 166 is varied. This, inturn, varies the magnitude of increment M for each variation in thepattern cams diameter. Since this setting is dependent on the convexcurve (normally selected as the mean between the major and minor axes),the lens blank is fed into the Wheel along this mean regardless of otherconsiderations.

In a general manner, While we have, in the above description, disclosedWhat we deem to be practical and efficient embodiments of our invention,it should be well understood that we do not wish to be limited thereto,as there might be changes made departing from the principle of thepresent invention as comprehended within the scope of the accompanyingclaims.

We claim:

1. A bevel edge grinder comprising in combination, a base, a lenscarrier supported on said base, said carrier comprising a first carriagefor reciprocation in a first direction across said base, a secondcarriage mounted on said first carriage for reciprocation in a seconddirection normal to said direction of movement of said first carriage, apattern cam for controlling the movement of the carrier in said firstdirection, an arm pivotally mounted about a point on said base, meanspivotally connecting said second carriage to said arm whereby for eachmovement in said first direction of said first carriage, a secondmovement in said second direction is caused in said econd carriage ascontrolled by the pivoting of said arm.

2. A bevel edge grinder comprising in combination, a base, a lenscarrier supported on said base, said carrier comprising a first carriagefor reciprocation in a first direction across said base, a secondcarriage mounted on said first carriage for reciprocation in a seconddirection normal to said direction of movement of said first carriage,and a chucking shaft mounted on said second carriage, a pattern cammounted at one end of said shaft, a cam abutment surface mounted on saidbase, means keeping said pattern cam against said surface therebycontrolling the movement of the carrier in said first direction, an armpivotally mounted about a point on said base, means pivotally connectingsaid second carriage to said arm such that for each movement in saidfirst direction of said first carriage, a second movement in said seconddirection is caused in said second carriage as controlled by thepivoting of said arm.

3. A bevel edge grinder comprising in combination, a support, a lenscarrier supported on said support, said carrier comprised of a base andtwo upstanding legs defining a saddle therebetween, a grinding wheel insaid saddle, a first carriage for reciprocation in a first directionacross said support, a second carriage mounted on said first carriagefor reciprocation in a second direction normal to said direction ofmovement of said first carriage and supporting said carrier, a patterncam on said carrier for controlling the movement thereof in said firstdirection, an arm pivotally moimted about a point on said upport, meanspivotally connecting said second carriage to said arm whereby for eachmovement in said first direction by said first carriage, a secondmovement in said second direction is caused in said second carriage ascontrolled by the pivoting of said arm.

4. A bevel edge grinder of a type to bevel the edge of a lens blankcomprising in combination, a base, a lens carrier supported on saidbase, a shaft rotatably secured in said carrier, said lens blanksupported at one end of said shaft, a pattern cam at the other endthereof having a peripheral configuration of that desired for said blankat the end of a grinding operation, a cam abutment surface stationarywith respect to base, means maintaining said pattern cam in engagementwith said surface as said shaft rotates, said carrier comprising a firstcarriage for reciprocation in a first direction across said base, asecond carriage mounted on said first carriage for reciprocation in asecond direction normal to said direction of movement of said firstcarriage, an arm pivotally mounted about a point on said base, meanspivotally connecting said second carriage to said arm whereby for eachmovement in said first direction by said first carriage, a secondmovement in said second direction is caused in said second carriage ascontrolled by the pivoting of said arm.

5. A bevel edge grinder of a type to bevel the edge of a lens blankcomprising in combination, a base, a grinding wheel supported on saidbase, a lens blank carrier supported on said base, said lens blanksupported by said carrier, means to move said blank into engagement withsaid wheel, said means comprising a first carriage for reciprocation ina first direction across said base, a second carriage mounted on saidfirst carriage for reciprocation in a second direction normal to saiddirection of movement of said first carriage, a pattern cam forcontrolling the movement of the carrier in said first direction, an armpivotally mounted about a first point on said base, means pivotallyconnecting said second carriage to said arm at a second point wherebyfor each movement of said first carriage in said first direction, asecond movement in said second direction is caused in said secondcarriage as controlled by the pivoting of said arm, and means to varythe distance of said second point with respect to said first point.

6. A bevel edge grinder of a type to bevel the edge of a lens blankhaving a particular convex surface curve comprising in combination, abase, a carrier supported on said base, said carrier comprising a firstcarriage for reciprocation in a first direction across said base, asecond carriage mounted on said first carriage for reciprocation in asecond direction normal to said direction of movement of said firstcarriage, a rotatable pattern cam for controlling the movement of thecarrier in said first direction, an arm pivotally mounted about a firstpoint on said base, means pivotally and adjustably connecting saidsecond carriage to a selected point on said arm whereby for eachmovement in said first direction, a second movement in said seconddirection is given to said second carriage and the combined movement isan are.

7. A bevel edge grinder of a type to bevel the periphery of a lens blankcomprising in combination, a base, a grinding wheel, a carrier supportedon said base, first means to accurately position said carrier withrespect to said wheel, a shaft rotatably mounted in said carrier, firstmeans mounting said blank to said shaft with the convex surface of saidblank adjacent one end of the shaft, second means for detecting thedistance of the apogee of said surface from said one end, and to movesaid carrier an amount equal to said distance, third means for movingsaid blank into engagement with said wheel, comprising a first carriagefor reciprocation in a first direction across said base, a secondcarriage mounted on said first carriage for back and forth movement in asecond direction normal to said first carriage, a pattern cam mounted onthe other end of said shaft for controlling the movement of the carrierin said first direction, an arm pivotally mounted about a point on saidbase, means pivotally connecting said second carriage to said armwhereby for each movement of said first carriage in said firstdirection, a second movement in said second direction is caused in saidsecond carriage as controlled by the pivoting of said arm.

8. A bevel edge grinder of a type to bevel the edge of a lens blankhaving a particular convex surface comprising in combination, a base,carrier supported on said base, said carrier comprising a first carriagefor reciprocation in a first direction across said base, a secondcarriage mounted on said first carriage for reciprocation in a seconddirection normal to said direction of movement of said first carriage, acam abutment surface mounted on said base, a rotatable pattern cammounted on said carrier, means causing said pattern cam to engage saidsurface as said pattern cam rotates for controlling the movement of thecarrier in said first direction, an arm pivotally mounted about a firstpoint on said base, means pivotally and adjustably connecting saidsecond carriage to a selected second point on said arm whereby for eachmovement in said first direction, a second movement in said seconddirection is given to said second carriage and the combined movement isan are dependent on the position of said first and second points.

9. A bevel edge grinder comprising in combination, a support, a lenscarrier supported on said support, said carrier comprised of a base andfirst and second upstanding legs defining a saddle therebetween, agrinding wheel in said saddle, a first carriage for reciprocation in afirst direction across said support, a second carriage mounted on saidfirst carriage for reciprocation in a second direction normal to saiddirection of movement of said first carriage and supporting saidcarrier, a rotatable shaft mounted in said first leg and having one endextending into said saddle, a second shaft having one end in said saddleand rotatably mounted in said second leg coaxial with said first shaft,and means for moving said second shaft axially toward and away from saidfirst shaft whereby a lens blank can be secured between said shafts, apattern cam on the other end of said shaft for controlling the movementof said carrier in said first direction, an arm pivotally mounted abouta point on said support, means pivotally connecting said second carriageto said arm such that for each movement in said first direction by saidfirst carriage, a second movement in said second direction by saidsecond carriage is accomplished and controlled by the pivoting of saidarm.

10. A bevel edge grinder comprising, in combination, a base, a lenscarrier supported on said base, said carrier comprising a first carriagefor reciprocation in a first direction across said base, a secondcarriage mounted on said first carriage for reciprocation in a seconddirection normal to said direction of movement of said first carriage, arotatable pattern cam mounted on said lens carrier for controlling themovement of the carrier in said first direction, an arm pivotallymounted about a first point on said base, means pivotally connectingsaid second carriage at a selected point along the length of said armsuch that for each movement in said first direction, a second movementin said second direction is caused in said second carriage as controlledby the pivoting of said arm, and second means for adjustably selectingthe distance between said first and second points.

11. A bevel edge grinder comprising, in combination, a base, a lenscarrier supported on said base, an abrading wheel having a V-groovemounted on said base, said carrier comprising a first carriage forreciprocation in a first direction across said base, a second carriagemounted on said first carriage for reciprocation in a second directionnormal to said direction of movement of said first means, and a rotatingchucking shaft mounted on said second carriage, a pattern cam mounted atone end of said shaft, a cam abutment surface mounted on said base,means maintaining said pattern cam in engagement with said surface assaid shaft rotates, thereby controlling the movement of said carrier insaid first direction, an arm pivotally mounted about a point on saidbase, means pivotally connecting said second carriage to said arm suchthat for each movement in said first direction, a second movement insaid second direction is accomplished as controlled by the pivoting ofsaid arm, said carrier receiving a combined movement toward saidV-groove, and the path of said movement determined by the extent of saidfirst and second movements.

12. A bevel edge grinder for beveling the periphery of a lens blankcomprising, in combination, a support, a lens carrier on said supportand carrying said lens blank, said carrier comprised of a base and twoupstanding sections defining a saddle therebetween, a grinding wheelhaving a V-groove disposed in said saddle, means for moving the edge ofsaid lens blank toward and away said V-groove along a selected path,said carrier comprising a first carriage for reciprocation in a firstdirection across said support, a second carriage mounted on said firstcarriage for reciprocation in a second direction normal to saiddirection of movement of said first carriage, and said second carriagesupporting said carrier to adjust said carrier with respect to saidfirst carriage, a rotating pattern cam on said carrier for controllingthe movement of said first carriage in said first direction, an armpivota ly mounted about a first point on said support, means pivotallyconnecting said second carriage to said arm at a second point along thelength of said arm whereby for each movement in said first direction, asecond movement by said second carriage in said second direction isaccomplished and controlled by the pivoting of said arm, the combinedmovement being said selected movement as determined by the distancebetween said first and second points.

13. A bevel edge grinder adapted to grind the edge of a lens blankcomprising, in combination, a base, a lens carrier supported on saidbase, a shaft rotatably secured in said carrier, said lens blanksupported at one end of said shaft, a pattern cam at the other endthereof having a peripheral configuration of that desired for said blankat the end of a grinding operation, a cam abutment surface stationarywith respect to base, an air cylinder operatively connected between saidbase and said carrier, keeping said cam pattern in engagement with saidsurface as said shaft rotates, means for adjusting the initial distancebetween said pattern cam and said surface, said carrier comprising afirst carriage for reciprocation in a first direction across said base,a second carriage mounted on said first carriage for reciprocation in asecond direction normal to said direction of movement of said firstcarriage, an arm pivotally mounted about a point on said base, meanspivotally connecting said second carriage to said arm whereby for eachmove ment in said first direction by said first carriage, a secondmovement by said second carriage in said second direction isaccomplished and controlled by the pivoting of said arm.

14. An edge grinder for beveling a lens blank comprising, incombination, a base, a grinding wheel supported on said base, a lensblank carrier supported on said base, a chuck supporting said blank onsaid carrier, said chuck comprised of a pair of shafts having chucksurfaces in opposed face-to-face relationship securing a lens blanktherebetween, air pressure means for moving one of said shafts towardand away from the other of said shafts, means to move said blank intoengagement with said wheel, said means comprising a first carriage forreciprocation in a first direction across said base, a second carriagemounted on said first carriage for reciprocation in a second directionnormal to said direction of movement of said first carriage, a patterncam for controlling the movement of the carrier in said first direction,an arm pivotally mounted about a point on said base, means pivotallyconnecting said second carriage to said arm whereby for each movement insaid first direction by said first carriage, a second movement in saidsecond direction by said second carriage is accomplished and controlledby the pivoting of said arm.

15. A bevel edge grinder for edging a meniscus-shaped article such as alens, comprising, in combination, a base, an abrading wheel supported onsaid base and rotatable about a first axis and having a peripherallydisposed substantially V-shaped abrading surface, a lens carrier on saidbase having means supporting the lens in edgewise engagement with saidV-shaped surface, said means being mounted for rotation about a secondaxis disposed at an angle to said first axis about which the abradingwheel is rotated whereby the plane defined by the apex of the V-shapedsurface is angularly disposed with respect to said second axis to causethe V-shaped surface to be effectively curved in the direction of thecurvature of the meniscus-shaped lens and said lens, when properlymounted by said means, having a predetermined center coaxial with saidsecond axis, said carrier comprising a first carriage for reciprocationin a first direction generally perpendicular to said second axis, asecond carriage mounted on said first carriage for simultaneousreciprocation in a second direction generally parallel to said secondaxis, control means for converting said first and second directions to acurvilinear path for said article toward and away from said V-shapedabrading surface.

16. The bevel edge grinder described in claim 15 wherein said controlmeans is comprised of a cam means mounted on said first carriage, an armpivotally secured to said first mentioned base and securing means foradjustably connecting said second carriage to a point along the lengthof said arm.

17. The bevel edge grinder described in claim 15 12 wherein the centerof curvature of said path is on one side of said plane defined by theapex of said V-shaped surface and the center of curvature of saidmeniscusshaped article is on the other side of said plane.

References Cited in the file of this patent UNITED STATES PATENTS2,451,137 White Oct. 12, 1948 2,612,734 Taig Oct. 7, 1952 2,651,149 FernSept. 8, 1953 2,693,063 Dillon Nov. 2, 1954 2,710,496 Okey June 14, 1955

1. A BEVEL EDGE GRINDER COMPRISING IN COMBINATION, A BASE, A LENSCARRIER SUPPORTED ON SAID BASE, SAID CARRIER COMPRISING A FIRST CARRIAGEFOR RECIPROCATION IN A FIRST DIRECTION ACROSS SAID BASE, A SECONDCARRIAGE MOUNTED ON SAID FIRST CARRIAGE FOR RECIPROCATION IN A SECONDDIRECTION NORMAL TO SAID DIRECTION OF MOVEMENT OF SAID FIRST CARRIAGE, APATTERN CAM FOR CONTROLLING THE MOVEMENT OF THE CARRIER IN SAID FIRSTDIRECTION, AN ARM PIVOTALLY MOUNTED ABOUT A POINT ON SAID BASE, MEANSPIVOTALLY CONNECTING SAID SECOND CARRIAGE TO SAID ARM WHEREBY FOR EACHMOVEMENT IN SAID FIRST DIRECTION OF SAID FIRST CARRIAGE, A SECONDMOVEMENT IN SAID SECOND DIRECTION IS CAUSED IN SAID SECOND CARRIAGE ASCONTROLLED BY THE PIVOTING OF SAID ARM.